This paper investigates the political and socio-economic drivers of energy transition at the local level in the United States. Using observations, public documents and semi-structured interviews from a sample of Connecticut (CT) towns, it explores why some local governments are more proactive than others in designing and implementing policies that promote renewable energy and greater energy efficiency. The research reveals that the type and configuration of policy champions matter in distinguishing among towns’ clean energy engagement levels. Those towns that can bring together elected, appointed and volunteer leaders who are active and passionate advocates for clean energy are generally more successful than others in carrying out clean energy policies. Leader towns are also those that have organized interest groups and businesses that support and work with the government in designing and implementing clean energy initiatives. The case studies further reveal that a town's wealth and education levels, but not its partisan affiliation, are important in shaping the will and capacity of town officials as well as of interest groups in society. Finally, the paper analyzes the institutional decision-making context and finds that while government type is not determinative, a town's bureaucratic capacity, measured in terms of the availability of specialized energy staff and energy task force, distinguishes leader towns from the rest. Developing a better understanding of the political will, government-society synergy, and institutional capacity is critical to a full accounting of the challenges and opportunities local governments face in clean energy transitions.